Dr. James Salwitz recently wrote a blog post about the tendency of doctors to over-test. He pointed out that ordering myriad tests will not necessarily provide for better medical care. The worst example, he wrote, is the ordering of an invasive test where the results won’t change what will be done to help the patient.
He cites an example of an 89-year old patient in whom lung nodules were found in a chest x-ray, probably from cancer metastasis. The doctor recommended a biopsy. When the patient asked what would happen if they proved to be cancerous, the answer was, of course, expensive and debilitating treatment that might prolong her life for a short while — or might not. The patient declined.
He blames part of the tendency to over-test for unlikely or extraordinarily rare conditions on the personality characteristics of doctors, coupled with their training. Physicians want to have a standard of exactitude, which is often not reasonable or practical. He writes “[doctors] stay awake at night because of a small probability that an obscure diagnosis might be missed because blood was not drawn, an x-ray not taken, or an orifice not invaded.” There is a tendency to expand the differential diagnosis to include diseases whose likelihood is remote.
The question that should be asked, says Dr. Salwitz, is: will the test results likely change the care that is provided?
In cases where patients are already very ill with a particular disease, should doctors be looking for other disease conditions? Dr. Salwitz cites the example of a patient with lung cancer, who presented with symptoms that might indicate unstable heart disease. So a cardiac catheterization was performed, with the result that the intravenous dye caused him to have sudden kidney failure. Dr. Salwitz points out that, before they invaded his heart and damaged his kidneys, they should have asked “Are we going to fix the coronary arteries of a patient with advanced lung cancer?”
Dr. Salwitz decries the tendency, often pushed by relatives, to continue to order x-rays and labs, even though the medical condition of the patient is beyond remediation. Intrusive testing, rather than comfort control, is the theme.
Rather than assuming that more tests are better, he says it is better to have a clear understanding of how a particular test is going to change the care plan. “A test only has value if it improves life.”
In his article, Dr. Salwitz does not comment on the dilemma of whether tests results are certain enough to justify changes in medical care. Examples are recent recommendations to pull back from routine breast imaging and PSA test reliance, because so often the results of false positives — expensive and often dangerous treatment — may outweigh the benefits of diagnosis.
